QUANTIFICATION OF ACTINIDE ALPHA-RADIATION DAMAGE IN MINERALS AND CERAMICS

Journal Article · Thu Jan 11 04:00:00 EST 2007 · Nature, 445:190-193

DOI:https://doi.org/10.1038/nature05425· OSTI ID:898087

Farnan, Ian E; Cho, Herman M; Weber, William J

There are large amounts of heavy alpha-emitters in nuclear waste and nuclear materials inventories stored in various sites around the world. These include plutonium and minor actinides such as americium and curium. In preparation for geological disposal there is a consensus that actinides that have been separated from spent nuclear fuel should be immobilised within mineral-based ceramics rather than glass. Over the long-term, the alpha-decay taking place in these ceramics will severely disrupt their crystalline structure and reduce their durability. A fundamental property in predicting cumulative radiation damage is the number of atoms permanently displaced per alpha–decay. Currently, this number is estimated as 1000-2000 atoms/alpha decay event. Here, we report nuclear magnetic resonance, spin-counting experiments that measure close to 5000 atoms/alpha decay event in radiation damaged natural zircons. New radiological NMR measurements on highly radioactive, 239Pu zircon show damage similar to that created by 238U and 232Th in mineral zircons at the same dose, indicating no significant effect of dose rate. Based on these measurements, the initially crystalline structure of a 10 wt% 239Pu zircon would be amorphous after only 1400 years in a geological repository. These measurements establish a basis for assessing the long-term structural durability of actinide-containing ceramics based on an atomistic understanding of the fundamental damage event.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 898087
• Report Number(s): PNNL-SA-51828; 19194; 19852; KP1301020
• Journal Information: Nature, 445:190-193, Journal Name: Nature, 445:190-193
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACTINIDES
ALPHA DECAY
AMERICIUM
ATOMS
Amorphization
CERAMICS
CURIUM
DECAY
DOSE RATES
Environmental Molecular Sciences Laboratory
GLASS
NMR
NUCLEAR FUELS
NUCLEAR MAGNETIC RESONANCE
PLUTONIUM
RADIATIONS
RADIOACTIVE WASTES
Radiation Damage
SPENT FUELS
ZIRCON
Zircon